The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 02, 1977
Filed:
Dec. 29, 1975
Joseph L Stein, Allegheny County, PA (US);
Walter S Treffner, Anne Arundel County, MD (US);
General Refractories Company, Bala Cynwyd, PA (US);
Abstract
This invention provides improved high fired direct bonded basic magnesite-chrome refractory shapes, such as brick, characterized by the presence of chromium enriched spinel structures distributed in the matrix and bonding the individual periclase crystals. The shapes are thermally stable and resistant to slag penetration and erosion and enjoy improved service life in industrial furnace linings. Also provided is a method of making the improved refractory shapes which comprises forming a mixture of (1) from about 40% to about 75% by weight high purity magnesite, (2) from about 25% to about 60% by weight chrome ore and (3) from about 0.5% to about 10% by weight chromic oxide powder; pressing the mixture into a refractory shape; and firing the refractory shape to a temperature of at least 1700.degree. C.